Goldman Sachs says that the Windows business is slowing Microsoft down, reiterating its "sell" rating in an analyst note issued today ahead of its quarterly earnings call next week.

In that note, Goldman Sachs refers to Windows as a "continued drag" and an impediment to growth.

Basically, Goldman says that it has observed three things around Windows in the course of its field work:

Not enough enterprises are going to move to Windows 10, at least not right away, denying Microsoft the income that comes from huge corporate contracts.

Windows Server 2003 is reaching its end-of-life, meaning Microsoft will no longer support it with new updates and patches. But it was never Microsoft's most popular product, so even if enterprises take the opportunity to upgrade, Goldman Sachs doubts it's enough to really make much impact on the bottom line.

Not enough enterprises are renewing their Enterprise License Agreements (ELAs), a bundle of software-plus-support packages that Microsoft offers to larger customers.

And while Microsoft Office 365, the cloud-based version of the megapopular productivity software, is still experiencing "strong momentum" in the enterprise, Goldman says, it's not actually driving up the value of many enterprise contracts.

Combine all of that with the declining market for desktop PCs in general, and things aren't looking good for Microsoft in the short term. Goldman Sachs is now predicting that Microsoft will report quarterly revenue of $22 billion, a tad lower than the $22.1 billion consensus.